Low birth weight and preterm births: etiologic fraction attributable to prenatal drug exposure

J Perinatol. 2005 Oct;25(10):631-7. doi: 10.1038/sj.jp.7211378.


Objectives: To determine the factors that would increase the likelihood of outcomes: low birth weight (LBW), preterm births and intrauterine growth restriction (IUGR).

Study design: Secondary data analysis from a multi-center study. Risk factors for each outcome were derived from logistic regression models. Odds ratios (OR), 95% confidence intervals, and population-attributable risk proportions (PAR%) were estimated.

Results: Prenatal cocaine exposure increased the likelihood of LBW (OR: 3.59), prematurity (OR: 1.25), and IUGR (OR: 2.24). Tobacco, but not marijuana, significantly influenced these outcomes. Alcohol had an effect on LBW and IUGR. Etiologic fractions (PAR%) attributable to tobacco for LBW, prematurity, and IUGR were 5.57, 3.66, and 13.79%, respectively. With additional drug exposure including cocaine, estimated summary PAR% increased to 7.20% (LBW), 5.68% (prematurity), and 17.96% (IUGR).

Conclusion: Disease burden for each outcome increases with each added drug exposure; however, etiologic fraction attributable to tobacco is greater than for cocaine.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cocaine / toxicity
  • Dose-Response Relationship, Drug
  • Female
  • Fetal Growth Retardation / chemically induced
  • Fetal Growth Retardation / etiology
  • Fetus / drug effects*
  • Humans
  • Infant, Low Birth Weight*
  • Infant, Newborn
  • Infant, Premature*
  • Obstetric Labor, Premature / etiology
  • Pregnancy
  • Risk Factors
  • Smoking / adverse effects


  • Cocaine